JPH04187948A - Refrigeration system - Google Patents

Abstract

PURPOSE:To prevent refrigerant from flowing in the opposite direction by a method wherein a liquid tank is connected to a charge modulator via a check valve, and liquid refrigerant stored in the charge modulator is supplied to the liquid tank at the same time of commencement of defrosting operation during heating operation. CONSTITUTION:When defrosting operation is started during heating operation, as an air-side heat exchanger 2 serves as a condenser and is in extremely cooled state, refrigerant condenses and stays in the air-side heat exchanger 2. As a result, refrigerant supply to a liquid tank 8 through a check valve 9 interrupts. On the other hand, as a charge modulator 7 is blocked by a check valve 12a although a water-side heat exchanger 3 serves as an evaporator, refrigerant supply begins only to the liquid tank 8 through a connecting pipe 13 and a check valve 12b. During this refrigerant supply, defrosting of the air-side heat exchanger 2 proceeds, causing the condensing pressure to begin rising, and the condensed liquid is supplied again to the liquid tank 8 through the check valve 9. Hence, the check valve 12b prevents the liquid from flowing from liquid tank 8 to the charge modulator 7 during cooling operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigeration system that includes a compressor in a refrigeration cycle that is cooled, lubricated, and sealed by injection of refrigerant liquid.

[Conventional technology]

Figure 2 is a refrigerant piping system diagram showing a conventional refrigeration system. In the figure, 1 is a compressor that is cooled, lubricated, and sealed by refrigerant liquid injection, and 2 is an air-side heat exchanger that functions as a condenser during cooling. 3 is a water side heat exchanger as an evaporator during cooling, 4a and 4b are switching valves that switch the flow of refrigerant during cooling and heating, 5 is an accumulator, 6 is an expansion valve, and 7 is during cooling and heating. A charge modulator that adjusts the difference in the amount of refrigerant required; 8 a liquid tank that stores refrigerant liquid for injection into the compressor 1; 9 a check valve; 10 a solenoid valve;
a, 1 l b, and 11 c are refrigerant pipes.

Next, the operation will be explained.

First, during cooling operation, refrigerant vapor generated from the water-side heat exchanger 3 serving as an evaporator is compressed by the compressor 1 through the accumulator 5, and the high-pressure superheated vapor resulting from this compression is transferred to the switching valve 4.
supplied to the air side heat exchanger 2 as a condenser via a,
Here, it becomes a refrigerant liquid by cooling. This high-pressure refrigerant liquid is then supplied to the expansion valve 6 via the switching valve 4b, where the pressure is reduced and the temperature is lowered. This reduced-pressure refrigerant is then evaporated in the water-side heat exchanger 3, taking the heat of evaporation from the surroundings.

It becomes low-pressure steam and is sent to the compressor 1. This compressor 1
Then, high-pressure superheated steam is supplied to the air-side heat exchanger 2, and the same operation is repeated thereafter. At this time, the flow of the refrigerant is in the direction of the solid arrow. In addition, during heating operation, the flow of the refrigerant (dotted line arrow) is reversed by switching the switching valves 4a and 4b, and the air side heat exchanger 2 is used as an evaporator, and the water side heat exchanger 3 is used as a condenser. used.

In addition, since the pipe 11a connecting the switching valve 4a and the air side heat exchanger 2 passes through the charge modulator tough,
During cooling, refrigerant gas from the compressor 1 flows through this pipe 11a.
The charge modulator 7 is heated. During heating, refrigerant gas flows to the compressor 1 and the charge modulator 7 is cooled. -For boat fishing, the amount of refrigerant required for heating is smaller than for cooling. For this reason, surplus refrigerant during heating is generated by passing the high-temperature, high-pressure refrigerant liquid condensed in the water-side heat exchanger 3, which functions as a condenser, through the refrigerant pipe 11b and collecting it in the cooled charge modulator tough. The amount of refrigerant within the refrigeration cycle system is adjusted. On the other hand, since cooling requires more refrigerant than heating, the amount of refrigerant is adjusted by supplying the insufficient refrigerant from the heated charge modulator 7 to the low-temperature, low-pressure water-side heat exchanger 3 through the pipe 11b. be done. In this way, the amount of refrigerant required during cooling and heating is adjusted.

On the other hand, the liquid tank 8 transfers a part of the refrigerant liquid condensed in the air-side heat exchanger 2 as a condenser to a check valve 9 and a solenoid valve 10.
is injected into the compressor 1. This prevents problems even if the supply of refrigerant is temporarily cut off at the time of startup or the start of defrosting. The check valve 9 also has a function to prevent the liquid stored in the liquid tank from flowing backward and decreasing even if the pressure on the air-side heat exchanger 2 side, which is a condenser, decreases due to unit stoppage, etc. have Further, the solenoid valve 10 opens and closes in conjunction with the start and stop of the compressor 1.

[Problem to be solved by the invention]

Since the conventional refrigeration system is configured as described above, the air-side heat exchanger 2, which is a condenser, cools down when the refrigeration cycle is started or when defrosting is started.

In order to avoid problems even if the liquid for liquid injection is not supplied until a large amount of liquid condenses and the pressure rises, the liquid tank 8 must be made larger, and the amount of extra refrigerant charged increases accordingly. However, there were problems such as disadvantages in terms of cost and space.

In addition, as such a conventional refrigeration system, Mitsubishi Electric, Mitsubishi air-cooled heat pump chiller, CAH type.

There is a similar description on page 5 of the technical manual for the medium thick series.

This invention was made in order to solve the above-mentioned problems, and provides a refrigeration system that can make the liquid tank that accommodates the refrigerant liquid for refrigerant liquid injection compact and, as a result, can reduce the total cost of the refrigeration cycle. The purpose is to

[Means to solve the problem]

In the refrigeration system according to the present invention, a liquid tank and a charge modulator are connected through a check valve, and the liquid refrigerant stored in the charge modulator is supplied to the liquid tank at the same time as defrosting starts during heating.

[Effect]

The check valve in the present invention functions to supply refrigerant liquid, which is insufficient in the refrigerant cycle during cooling operation, from the charge modulator to the liquid tank, and also functions to prevent the flow of refrigerant in the opposite direction.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 12a is a check valve provided in the middle of the pipe 11b, 12b is a check valve provided between the charge modulator 7 and the liquid tank 8, and 13 is a connection pipe. Note that other constituent parts that are the same as those shown in FIG. 2 are given the same reference numerals, and redundant explanation thereof will be omitted.

Next, the operation will be explained.

First, in the refrigeration cycle during heating, the refrigerant flows as described above, and at this time, excess refrigerant from the compressor 1 flows through the water side heat exchanger 3. Refrigerant pipe 11b, check valve 12
A can be stored in the charge modulator tough one after another. In this case, although the charge modulator 7 is connected to the liquid tank 8 by the piping 13, since the liquid tank 8 is filled with refrigerant liquid during heating, there is no movement of liquid from the charge modulator 7. If the air-side heat exchanger 2 becomes frosted due to the continuation of such heating operation, then defrosting will start. In this case, the air-side heat exchanger 2 functions as a condenser, but since it is completely cold, the refrigerant condenses in the air-side heat exchanger 2 and remains there. Therefore, the liquid refrigerant supplied to the liquid tank 8 through the check valve 9 is interrupted.

On the other hand, in the charge modulator 7, although the water side heat exchanger 3 functions as an evaporator, it is shut off by the check valve 12a, so the refrigerant liquid is not supplied to the liquid tank 8 via the connection pipe 13 and the check valve 12b. Start supplying. During this supply, defrosting in the air-side heat exchanger 2 progresses, the condensing pressure also begins to rise, and the condensed liquid is again supplied to the liquid tank 8 through the check valve 9. Here, the check valve 12b prevents liquid from flowing back from the liquid tank 8 to the charge modulator 7 during cooling operation.

In the above embodiment, the connection pipe 13 is connected to the liquid tank 8, but the connection pipe 13 may be connected to the refrigerant pipe 11c between the liquid tank 8 and the electromagnetic valve 10. The same effects as in the embodiment are achieved.

〔Effect of the invention〕

As described above, according to the present invention, the liquid tank and the charge modulator are connected through the check valve.

Since the configuration is such that the liquid refrigerant stored in the charge modulator during heating is supplied to the liquid tank at the same time as defrosting starts, the liquid refrigerant stored in the charge modulator is It can be used as a refrigerant for liquid injection, and as a result, the capacity of the liquid tank can be reduced and the size can be made more compact, and the total amount of refrigerant sealed in the refrigeration cycle can be kept small.

This has the effect of producing something that can reduce costs.

[Brief explanation of drawings]

FIG. 1 is a refrigerant piping system diagram showing a refrigeration system according to an embodiment of the present invention, and FIG. 2 is a refrigerant piping system diagram showing a conventional refrigeration system. 1 is a compressor, 2 is a condenser (air side heat exchanger), 3 is an evaporator (water side heat exchanger), 6 is an expansion valve, 7 is a charge modulator, 8 is a liquid tank, and 11a. 11b and llc are refrigerant pipes, and 12b is a check valve. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A refrigeration cycle in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected by refrigerant piping, a liquid tank that receives and stores the refrigerant liquid injected by the compressor from the condenser, and acts as a condenser during heating. A refrigeration system comprising a charge modulator that collects high-temperature, high-pressure refrigerant liquid from the evaporator and supplies the collected refrigerant liquid to the refrigeration cycle system during cooling or when starting defrosting. A refrigeration system characterized in that a liquid tank and a charge modulator are connected via a check valve for supplying refrigerant liquid from the charge modulator to the liquid tank.